3.1 - Acids, alkalis and ions
Learn which ions acids and alkalis supply in water, and how their formulae distinguish ions from neutral atoms or molecules.
Ions in water
An aqueous solution is a solution in water; the state symbol (aq) means dissolved in water. Dissolved particles are spread throughout the liquid.
An acid in aqueous solution is a source of hydrogen ions, H⁺. An alkali in aqueous solution is a source of hydroxide ions, OH⁻. For example, hydrochloric acid supplies H⁺ and chloride ions, while sodium hydroxide solution supplies sodium ions and OH⁻.
| Solution | Characteristic ion supplied | Charge on that ion |
|---|---|---|
| Acid | H⁺, hydrogen ion | +1 |
| Alkali | OH⁻, hydroxide ion | −1 |
The charges are part of the formulae. H is a neutral hydrogen atom, H₂ is a hydrogen molecule, and H⁺ is a hydrogen ion. OH⁻ contains one oxygen and one hydrogen atom with an overall −1 charge; writing just OH does not show the hydroxide ion.
Continue this lesson.
You’re previewing NovaLearn without an account. Create a free account to read the rest.
Create free account